Multifiles C code to single Go code

[Konstantin8105]

Now, we have the problem in multifile transpilation is separating #define on each file.
Solution
Example : c2go transpile 1.c 2.c 3.c ....

1. Find all definition for 1.c like that:

clang -dM -E  1.c

Output:

#define BUFSIZ _IO_BUFSIZ
#define EOF (-1)
#define FILENAME_MAX 4096
#define FOPEN_MAX 16
#define L_ctermid 9
#define L_tmpnam 20
#define NULL ((void*)0)
...

2. Transfer definition to file 2.c. Used -D of clang.
3. ...
   Link for help: https://clang.llvm.org/docs/ClangCommandLineReference.html#dumping-preprocessor-state

Main task for issue: Transling sqlite files shell.c and sqlite3.c in one.

Last trying: https://github.com/Konstantin8105/c2go/blob/e70dfa5765eff7e05fdefaa754bf5c62b4a3986b/travis/test.sh

[elliotchance]

There is only two ways to transpile multiple files correctly:

1. Merge all of the C files into a single C file to preprocess and transpile, resulting in one large Go file. (This is what we do as of v0.17.0).
2. Transpile each C file completely independently (they do not affect each other at all) generating one Go file for each input C file. Then we remove the duplicated after the Go is produced. This is where we hope to get to. See Unused types, constants, vars #232 (comment).